Effect of Soil Test Crop Response Approach on Growth and Yield of Rabi Onion in Inceptisols

A field experiment of fertilizer equation validation was carried out during the Rabi season of 2022-23 to determine the effect of the Soil Test Crop Response (STCR) target equation on the growth and yield of Rabi onion. The experiment was laid out in a randomized block design with ten treatment combinations viz., Absolute Control, Generalised Recommended Dose of Fertilizer (GRDF) 100: 50: 50 N P2O5 K2O Kg ha-1 + FYM 25 t ha-1, As per Soil Test, STCRC target for 250 q ha-1 without vermicompost, STCRC target for 300 q ha-1 without vermicompost, STCRC target for 350 q ha-1 without vermicompost + Biofertilizer, STCRC target for 250 q ha-1 with vermicompost, STCRC target for 300 q ha-1 with vermicompost, STCRC target for 300 q ha-1 with vermicompost + Biofertilizer, Only 5 t ha-1 vermicompost. The research findings revealed that treatment T9 resulted in a significantly higher number of leaves (8.56 and 11.52) at 40 and 80 days after transplanting (DAT), height of crop (42.00 and 57.46 cm) at 40 and 80 days after transplanting (DAT), Chlorophyll (41.30 and 51.84) at 45 and 60 days after transplanting (DAT), polar and equatorial diameter (6.36 and 9.48 cm), neck girth (4.94 cm) and bulb weight (64.09 gm). Similarly, the treatment T9- STCRC target for 300 q ha-1 with vermicompost + Biofertilizer achieved significantly superior bulb yield (363.67 q ha-1) with per cent deviation of 3.90 % and top yield (67.18 q ha-1).